Cartridge and electrophotographic image forming apparatus which uses cartridge

Abstract

A cartridge for use with a main assembly of an electrophotographic image forming apparatus, the main assembly including a driving shaft having a rotational force applying portion, wherein the cartridge is dismountable from the main assembly in a direction substantially perpendicular to an axial direction of the driving shaft, the cartridge including i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis thereof; and ii) a coupling member engageable with the rotational force applying portion to receive a rotational force for rotating the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller and a disengaging angular position in which the coupling member is inclined away from the rotational force transmitting angular position, wherein when the cartridge is dismounted from the main assembly of the electrophotographic image forming apparatus in a direction substantially perpendicular to the axis of the developing roller, the coupling member moves from the rotational force transmitting angular position to the disengaging angular position.

The invention claimed is: 
     
       1. A process cartridge comprising:
 a casing; 
 a developing roller having a roller axis, the developing roller being rotatably supported in the casing to permit rotation about the roller axis; 
 a photosensitive drum having a drum axis, the photosensitive drum being rotatably supported in the casing to permit rotation about the drum axis; 
 a first coupling member having an axis, the first coupling member including (i) a first end portion operatively connected to the developing roller, (ii) a second end portion, and (iii) a connecting portion connecting the first end portion and the second end portion; and 
 a second coupling member having an axis, the second coupling member including a projection, 
 wherein the first coupling member is movable between a first position in which the axis of the first coupling member is substantially parallel to the roller axis, and a second position in which the axis of the first coupling member is inclined with respect to the roller axis, and 
 wherein a maximum angle of inclination of the axis of the first coupling member with respect to the roller axis is about 20 degrees to about 60 degrees. 
 
     
     
       2. The process cartridge according  claim 1 , wherein a maximum angle of inclination of the axis of the first coupling member is about 35 degrees. 
     
     
       3. The process cartridge according to  claim 1 , wherein a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the connecting portion of the first coupling member along a line perpendicular to the axis of the first coupling member is less than a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the second end portion along a line perpendicular to the axis of the first coupling member. 
     
     
       4. The process cartridge according to  claim 1 , wherein the projection has a plurality of corners in cross section. 
     
     
       5. The process cartridge according to  claim 1 , wherein the connecting portion of the first coupling member comprises a shaft along the axis of the first coupling member. 
     
     
       6. The process cartridge according to  claim 1 , wherein, for at least part of the second end portion of the first coupling member, a maximum distance from the axis of the first coupling member to an outermost surface along a line perpendicular to the axis of the first coupling member increases as the distance along the axis of the first coupling member from the connecting portion of the first coupling member increases. 
     
     
       7. The process cartridge according to  claim 1 , wherein the second end portion of the first coupling member comprises a projection, and the second end portion of the first coupling member comprises an opening to a surface forming a recess, with the surface facing away from the connecting portion of the first coupling member. 
     
     
       8. The process cartridge according to  claim 1 , wherein the axis of the first coupling member at the first position of the first coupling member is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       9. The process cartridge according to  claim 1 , further comprising a rotational force receiving gear for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the rotational force receiving gear. 
 
     
     
       10. The process cartridge according to  claim 9 , wherein a rotational axis of the rotational force receiving gear is offset from and substantially parallel to the roller axis. 
     
     
       11. The process cartridge according to  claim 10 , further comprising a developing roller gear that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the rotational force receiving gear to the developing roller through the developing roller gear. 
 
     
     
       12. The process cartridge according to  claim 11 , wherein the rotational force receiving gear meshes with the developing roller gear. 
     
     
       13. The process cartridge according to  claim 1 , further comprising a first rotational force receiving member for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the first rotational force receiving member. 
 
     
     
       14. The process cartridge according to  claim 13 , wherein a rotational axis of the first rotational force receiving member is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       15. The process cartridge according to  claim 14 , further comprising a second rotational force receiving member that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the first rotational force receiving member to the developing roller through the second rotational force receiving member, and 
 wherein the second coupling member is provided at a longitudinal end of the photosensitive drum. 
 
     
     
       16. The process cartridge according to  claim 1 , wherein the casing includes a first frame rotatably supporting the developing roller and a second frame rotatably supporting the photosensitive drum. 
     
     
       17. The process cartridge according to  claim 16 , wherein the second frame includes a projection positioned adjacent to the second coupling member. 
     
     
       18. The process cartridge according to  claim 1 , further comprising a spring for urging the first coupling member from the first position toward the second position. 
     
     
       19. A process cartridge comprising:
 a casing; 
 toner contained within the casing; 
 a developing roller having a roller axis, the developing roller being rotatably supported in the casing to permit rotation about the roller axis; 
 a photosensitive drum having a drum axis, the photosensitive drum being rotatably supported in the casing to permit rotation about the drum axis; 
 a first coupling member having an axis, the first coupling member including (i) a first end portion operatively connected to the developing roller, (ii) a second end portion, and (iii) a connecting portion connecting the first end portion and the second end portion; and 
 a second coupling member having an axis, the second coupling member including a projection, 
 wherein the first coupling member is movable between a first position in which the axis of the first coupling member is substantially parallel to the roller axis, and a second position in which the axis of the first coupling member is inclined with respect to the roller axis, and 
 wherein a maximum angle of inclination of the axis of the first coupling member with respect to the roller axis is about 20 degrees to about 60 degrees. 
 
     
     
       20. The process cartridge according  claim 19 , wherein a maximum angle of inclination of the axis of the first coupling member is about 35 degrees. 
     
     
       21. The process cartridge according to  claim 19 , wherein a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the connecting portion of the first coupling member along a line perpendicular to the axis of the first coupling member is less than a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the second end portion along a line perpendicular to the axis of the first coupling member. 
     
     
       22. The process cartridge according to  claim 19 , wherein the projection has a plurality of corners in cross section. 
     
     
       23. The process cartridge according to  claim 19 , wherein the connecting portion of the first coupling member comprises a shaft along the axis of the first coupling member. 
     
     
       24. The process cartridge according to  claim 19 , wherein, for at least part of the second end portion of the first coupling member, a maximum distance from the axis of the first coupling member to an outermost surface along a line perpendicular to the axis of the first coupling member increases as the distance along the axis of the first coupling member from the connecting portion of the first coupling member increases. 
     
     
       25. The process cartridge according to  claim 19 , wherein the second end portion of the first coupling member comprises a projection, and the second end portion of the first coupling member comprises an opening to a surface forming a recess, with the surface facing away from the connecting portion of the first coupling member. 
     
     
       26. The process cartridge according to  claim 19 , wherein the axis of the first coupling member at the first position is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       27. The process cartridge according to  claim 19 , further comprising a rotational force receiving gear for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the rotational force receiving gear. 
 
     
     
       28. The process cartridge according to  claim 27 , wherein a rotational axis of the rotational force receiving gear is offset from and substantially parallel to the roller axis. 
     
     
       29. The process cartridge according to  claim 28 , further comprising a developing roller gear that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the rotational force receiving gear to the developing roller through the developing roller gear. 
 
     
     
       30. The process cartridge according to  claim 29 , wherein the rotational force receiving gear meshes with the developing roller gear. 
     
     
       31. The process cartridge according to  claim 19 , further comprising a first rotational force receiving member for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the first rotational force receiving member. 
 
     
     
       32. The process cartridge according to  claim 31 , wherein a rotational axis of the first rotational force receiving member is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       33. The process cartridge according to  claim 32 , further comprising a second rotational force receiving member that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the first rotational force receiving member to the developing roller through the second rotational force receiving member, and 
 wherein the second coupling member is provided at a longitudinal end of the photosensitive drum. 
 
     
     
       34. The process cartridge according to  claim 19 , wherein the casing includes a first frame rotatably supporting the developing roller and a second frame rotatably supporting the photosensitive drum. 
     
     
       35. The process cartridge according to  claim 34 , wherein the second frame includes a projection positioned adjacent to the second coupling member. 
     
     
       36. The process cartridge according to  claim 19 , further comprising a spring for urging the first coupling member from the first position toward the second position. 
     
     
       37. A process cartridge comprising:
 a casing; 
 a developing roller having a roller axis, the developing roller being rotatably supported in the casing to permit rotation about the roller axis; 
 a photosensitive drum having a drum axis, the photosensitive drum being rotatably supported in the casing to permit rotation about the drum axis; 
 a first coupling member having an axis, the first coupling member being operatively connected to the developing roller, and the first coupling member being movable between (i) a first position in which the axis of the first coupling member is substantially parallel to the roller axis and (ii) a second position in which the axis of the first coupling member is inclined with respect to the roller axis; and 
 a second coupling member having an axis, the second coupling member being operatively connected to the photosensitive drum, and the second coupling member including a projection having a plurality of corners in cross section. 
 
     
     
       38. The process cartridge according to  claim 37 , wherein a maximum angle of inclination of the axis of the first coupling member with respect to the roller axis is about 20 degrees to about 60 degrees. 
     
     
       39. The process cartridge according  claim 38 , wherein a maximum angle of inclination of the axis of the first coupling member is about 35 degrees. 
     
     
       40. The process cartridge according to  claim 37 , wherein the first coupling member includes (i) a first end portion operatively coupled to the developing roller, (ii) a second end portion opposite to the first end portion, and (iii) a connecting portion connecting the first end portion and the second end portion, and
 wherein a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the connecting portion along a line perpendicular to the axis of the first coupling member is less than a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the second end portion along a line perpendicular to the axis of the first coupling member. 
 
     
     
       41. The process cartridge according to  claim 40 , wherein the connecting portion comprises a shaft along the axis of the first coupling member. 
     
     
       42. The process cartridge according to  claim 40 , wherein, for at least part of the second end portion, a maximum distance from the axis of the first coupling member to an outermost surface along a line perpendicular to the axis of the coupling member increases as the distance along the axis of the coupling member from the connecting portion increases. 
     
     
       43. The process cartridge according to  claim 40 , wherein the second end portion comprises the projection, and the second end portion comprises an opening to a recess, with a surface of the recess facing away from the connecting portion. 
     
     
       44. The process cartridge according to  claim 37 , wherein the axis of the first coupling member at the first position is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       45. The process cartridge according to  claim 37 , further comprising a rotational force receiving gear for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the rotational force receiving gear. 
 
     
     
       46. The process cartridge according to  claim 45 , wherein a rotational axis of the rotational force receiving gear is offset from and substantially parallel to the roller axis. 
     
     
       47. The process cartridge according to  claim 46 , further comprising a developing roller gear that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the rotational force receiving gear to the developing roller through the developing roller gear. 
 
     
     
       48. The process cartridge according to  claim 47 , wherein the rotational force receiving gear meshes with the developing roller gear. 
     
     
       49. The process cartridge according to  claim 37 , further comprising a first rotational force receiving member for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the first rotational force receiving member. 
 
     
     
       50. The process cartridge according to  claim 49 , wherein a rotational axis of the first rotational force receiving member is offset from and substantially parallel to the roller axis, and
 wherein a rotational axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       51. The process cartridge according to  claim 50 , further comprising a second rotational force receiving member that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the first rotational force receiving member to the developing roller through the second rotational force receiving member, and 
 wherein the second coupling member is provided at a longitudinal end of the photosensitive drum. 
 
     
     
       52. The process cartridge according to  claim 37 , wherein the casing includes a first frame rotatably supporting the developing roller and a second frame rotatably supporting the photosensitive drum. 
     
     
       53. The process cartridge according to  claim 52 , wherein the second frame includes a projection positioned adjacent to the second coupling member. 
     
     
       54. The process cartridge according to  claim 37 , further comprising a spring for urging the first coupling member from the first position toward the second position. 
     
     
       55. A process cartridge comprising:
 a casing; 
 toner contained within the casing; 
 a developing roller having a roller axis, the developing roller being rotatably supported in the casing to permit rotation about the roller axis; 
 a photosensitive drum having a drum axis, the photosensitive drum being rotatably supported in the casing to permit rotation about the drum axis; 
 a first coupling member having an axis, the first coupling member being operatively connected to the developing roller, and the first coupling member being movable between (i) a first position in which the axis of the first coupling member is substantially parallel to the roller axis and (ii) a second position in which the axis of the first coupling member is inclined with respect to the roller axis; and 
 a second coupling member having an axis, the second coupling member being operatively connected to the photosensitive drum, and the second coupling member including a projection having a plurality of corners in cross section. 
 
     
     
       56. The process cartridge according to  claim 55 , wherein a maximum angle of inclination of the axis of the first coupling member with respect to the roller axis is about 20 degrees to about 60 degrees. 
     
     
       57. The process cartridge according  claim 56 , wherein a maximum angle of inclination of the axis of the first coupling member is about 35 degrees. 
     
     
       58. The process cartridge according to  claim 55 , wherein the first coupling member includes (i) a first end portion operatively coupled to the developing roller, (ii) a second end portion opposite to the first end portion, and (iii) a connecting portion connecting the first end portion and the second end portion, and
 wherein a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the connecting portion along a line perpendicular to the axis of the first coupling member is less than a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the second end portion along a line perpendicular to the axis of the first coupling member. 
 
     
     
       59. The process cartridge according to  claim 58 , wherein the connecting portion comprises a shaft along the axis of the first coupling member. 
     
     
       60. The process cartridge according to  claim 58 , wherein, for at least part of the second end portion, a maximum distance from the axis of the first coupling member to an outermost surface along a line perpendicular to the axis of the coupling member increases as the distance along the axis of the coupling member from the connecting portion increases. 
     
     
       61. The process cartridge according to  claim 58 , wherein the second end portion comprises the projection, and the second end portion comprises an opening to a recess, with a surface of the recess facing away from the connecting portion. 
     
     
       62. The process cartridge according to  claim 55 , wherein the axis of the first coupling member at the first position is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       63. The process cartridge according to  claim 55 , further comprising a rotational force receiving gear for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the rotational force receiving gear. 
 
     
     
       64. The process cartridge according to  claim 63 , wherein a rotational axis of the rotational force receiving gear is offset from and substantially parallel to the roller axis. 
     
     
       65. The process cartridge according to  claim 64 , further comprising a developing roller gear that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the rotational force receiving gear to the developing roller through the developing roller gear. 
 
     
     
       66. The process cartridge according to  claim 65 , wherein the rotational force receiving gear meshes with the developing roller gear. 
     
     
       67. The process cartridge according to  claim 55 , further comprising a first rotational force receiving member for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the first rotational force receiving member. 
 
     
     
       68. The process cartridge according to  claim 67 , wherein a rotational axis of the first rotational force receiving member is offset from and substantially parallel to the roller axis, and
 wherein a rotational axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       69. The process cartridge according to  claim 67 , further comprising a second rotational force receiving member that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the first rotational force receiving member to the developing roller through the second rotational force receiving member, and 
 wherein the second coupling member is provided at a longitudinal end of the photosensitive drum. 
 
     
     
       70. The process cartridge according to  claim 55 , wherein the casing includes a first frame rotatably supporting the developing roller and a second frame rotatably supporting the photosensitive drum. 
     
     
       71. The process cartridge according to  claim 70 , wherein the second frame includes a projection positioned adjacent to the second coupling member. 
     
     
       72. The process cartridge according to  claim 55 , further comprising a spring for urging the first coupling member from the first position toward the second position. 
     
     
       73. A process cartridge comprising:
 a casing; 
 a developing roller having a roller axis, the developing roller being rotatably supported in the casing to permit rotation about the roller axis; 
 a photosensitive drum having a drum axis, the photosensitive drum being rotatably supported in the casing to permit rotation about the drum axis; 
 a first coupling member having an axis, the first coupling member being operatively connected to the developing roller, and the first coupling member being movable between (i) a first position in which the axis of the first coupling member is substantially parallel to the roller axis and (ii) a second position in which the axis of the first coupling member is inclined with respect to the roller axis; and 
 a second coupling member having an axis, the second coupling member being operatively connected to the photosensitive drum, and the second coupling member including a projection having a plurality of corners in cross section, 
 wherein the first coupling member and the second coupling member are disposed at same side of the casing in a direction of the drum axis. 
 
     
     
       74. The process cartridge according to  claim 73 , wherein a maximum angle of inclination of the axis of the first coupling member with respect to the roller axis is about 20 degrees to about 60 degrees. 
     
     
       75. The process cartridge according  claim 74 , wherein a maximum angle of inclination of the axis of the first coupling member is about 35 degrees. 
     
     
       76. The process cartridge according to  claim 73 , wherein the first coupling member includes (i) a first end portion operatively coupled to the developing roller, (ii) a second end portion opposite to the first end portion, and (iii) a connecting portion connecting the first end portion and the second end portion, and
 wherein a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the connecting portion along a line perpendicular to the axis of the first coupling member is less than a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the second end portion along a line perpendicular to the axis of the first coupling member. 
 
     
     
       77. The process cartridge according to  claim 76 , wherein the connecting portion comprises a shaft along the axis of the first coupling member. 
     
     
       78. The process cartridge according to  claim 76 , wherein, for at least part of the second end portion, a maximum distance from the axis of the first coupling member to an outermost surface along a line perpendicular to the axis of the coupling member increases as the distance along the axis of the coupling member from the connecting portion increases. 
     
     
       79. The process cartridge according to  claim 76 , wherein the second end portion comprises the projection, and the second end portion comprises an opening to a recess, with a surface of the recess facing away from the connecting portion. 
     
     
       80. The process cartridge according to  claim 73 , wherein the axis of the first coupling member at the first position is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       81. The process cartridge according to  claim 73 , further comprising a rotational force receiving gear for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the rotational force receiving gear. 
 
     
     
       82. The process cartridge according to  claim 81 , wherein a rotational axis of the rotational force receiving gear is offset from and substantially parallel to the roller axis. 
     
     
       83. The process cartridge according to  claim 82 , further comprising a developing roller gear that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the rotational force receiving gear to the developing roller through the developing roller gear. 
 
     
     
       84. The process cartridge according to  claim 83 , wherein the rotational force receiving gear meshes with the developing roller gear. 
     
     
       85. The process cartridge according to  claim 73 , further comprising a first rotational force receiving member for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the first rotational force receiving member. 
 
     
     
       86. The process cartridge according to  claim 85 , wherein a rotational axis of the first rotational force receiving member is offset from and substantially parallel to the roller axis, and
 wherein a rotational axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       87. The process cartridge according to  claim 86 , further comprising a second rotational force receiving member that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the first rotational force receiving member to the developing roller through the second rotational force receiving member, and 
 wherein the second coupling member is provided at a longitudinal end of the photosensitive drum. 
 
     
     
       88. The process cartridge according to  claim 73 , wherein the casing includes a first frame rotatably supporting the developing roller and a second frame rotatably supporting the photosensitive drum. 
     
     
       89. The process cartridge according to  claim 88 , wherein the second frame includes a projection positioned adjacent to the second coupling member. 
     
     
       90. The process cartridge according to  claim 73 , further comprising a spring for urging the first coupling member from the first position toward the second position. 
     
     
       91. A process cartridge comprising:
 a casing; 
 toner contained within the casing; 
 a developing roller having a roller axis, the developing roller being rotatably supported in the casing to permit rotation about the roller axis; 
 a photosensitive drum having a drum axis, the photosensitive drum being rotatably supported in the casing to permit rotation about the drum axis; 
 a first coupling member having an axis, the first coupling member being operatively connected to the developing roller, and the first coupling member being movable between (i) a first position in which the axis of the first coupling member is substantially parallel to the roller axis and (ii) a second position in which the axis of the first coupling member is inclined with respect to the roller axis; and 
 a second coupling member having an axis, the second coupling member being operatively connected to the photosensitive drum, and the second coupling member includes a projection having a plurality of corners in cross section, 
 wherein the first coupling member and the second coupling member are disposed at same side of the casing in a direction of the drum axis. 
 
     
     
       92. The process cartridge according to  claim 91 , wherein a maximum angle of inclination of the axis of the first coupling member with respect to the roller axis is about 20 degrees to about 60 degrees. 
     
     
       93. The process cartridge according  claim 92 , wherein a maximum angle of inclination of the axis of the first coupling member is about 35 degrees. 
     
     
       94. The process cartridge according to  claim 91 , wherein the first coupling member includes (i) a first end portion operatively coupled to the developing roller, (ii) a second end portion opposite to the first end portion, and (iii) a connecting portion connecting the first end portion and the second end portion, and
 wherein a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the connecting portion along a line perpendicular to the axis of the first coupling member is less than a maximum distance from the axis of the first coupling member to an outermost surface of at least part of the second end portion along a line perpendicular to the axis of the first coupling member. 
 
     
     
       95. The process cartridge according to  claim 94 , wherein the connecting portion comprises a shaft along the axis of the first coupling member. 
     
     
       96. The process cartridge according to  claim 94 , wherein, for at least part of the second end portion, a maximum distance from the axis of the first coupling member to an outermost surface along a line perpendicular to the axis of the coupling member increases as the distance along the axis of the coupling member from the connecting portion increases. 
     
     
       97. The process cartridge according to  claim 94 , wherein the second end portion comprises the projection, and the second end portion comprises an opening to a recess, with a surface of the recess facing away from the connecting portion. 
     
     
       98. The process cartridge according to  claim 91 , wherein the axis of the first coupling member at the first position is offset from and substantially parallel to the roller axis, and
 wherein the axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       99. The process cartridge according to  claim 91 , further comprising a rotational force receiving gear for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the rotational force receiving gear. 
 
     
     
       100. The process cartridge according to  claim 99 , wherein a rotational axis of the rotational force receiving gear is offset from and substantially parallel to the roller axis. 
     
     
       101. The process cartridge according to  claim 100 , further comprising a developing roller gear that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the rotational force receiving gear to the developing roller through the developing roller gear. 
 
     
     
       102. The process cartridge according to  claim 101 , wherein the rotational force receiving gear meshes with the developing roller gear. 
     
     
       103. The process cartridge according to  claim 91 , further comprising a first rotational force receiving member for receiving a rotational force from the first coupling member,
 wherein the first coupling member is pivotably connected to the first rotational force receiving member. 
 
     
     
       104. The process cartridge according to  claim 103 , wherein a rotational axis of the first rotational force receiving member is offset from and substantially parallel to the roller axis, and
 wherein a rotational axis of the second coupling member is substantially coaxial with the drum axis. 
 
     
     
       105. The process cartridge according to  claim 103 , further comprising a second rotational force receiving member that is provided at a longitudinal end of the developing roller,
 wherein the rotational force is transmitted from the first rotational force receiving member to the developing roller through the second rotational force receiving member, and 
 wherein the second coupling member is provided at a longitudinal end of the photosensitive drum. 
 
     
     
       106. The process cartridge according to  claim 91 , wherein the casing includes a first frame rotatably supporting the developing roller and a second frame rotatably supporting the photosensitive drum. 
     
     
       107. The process cartridge according to  claim 106 , wherein the second frame includes a projection positioned adjacent to the second coupling member. 
     
     
       108. The process cartridge according to  claim 91 , further comprising a spring for urging the first coupling member from the first position toward the second position.